The pharynx of Caenorhabditis elegans is a nearly self-contained neuromuscular organ responsible for feeding. To identify genes involved in the development or function excitable cells pharynx, I screened worms with visible defects pharyngeal feeding behavior. Fifty-two mutations identified 35 genes, at least 22 previously unknown. broke down into three broad classes: 2 pha which caused shape 7 phm contractile structures muscle, and 26 eat mutants had abnormal muscle motions, but normally...

The ability of organisms to evolve resistance threatens the effectiveness every antibiotic drug. We show that in nematode Caenorhabditis elegans, simultaneous mutation three genes, avr-14, avr-15 , and glc-1 encoding glutamate-gated chloride channel (GluCl) α-type subunits confers high-level antiparasitic drug ivermectin. In contrast, mutating any two genes modest or no resistance. propose a model which ivermectin sensitivity C. elegans is mediated by affecting parallel genetic pathways...

A guanylyl cyclase (GC-D) was recently shown to be expressed in a subclass of neurons within the neuroepithelim rat, but given that only single discovered, whether it represents an odorant/pheromone receptor as has been suggested for large family seven-transmembrane receptors remains unclear. Through cloning and expression cDNA we now demonstrate at least 29 genomic or sequences found Caenorhabditis elegans represent cyclases. Many membrane forms retain cysteine residues conserved...

Animals have evolved diverse behaviors that serve the purpose of finding food in environment. We investigated seeking strategy soil bacteria-eating nematode Caenorhabditis elegans. C. elegans bacterial varies quality: some species are easy to eat and support worm growth well, while others do not. show worms exhibit dietary choice: they hunt for high quality leave hard-to-eat bacteria. This behavior is enhanced animals already experienced good food. When hunting food, alternate between two...

Abstract Caenorhabditis elegans concentrates its food, bacteria, by pharyngeal pumping. The rate of pumping is affected the presence bacteria. Using a new assay that allows measurement in population worms suspended liquid measuring their uptake microscopic iron particles, we have confirmed and quantitated this effect. Furthermore, demonstrated starvation stimulates Worms had been deprived bacteria for more than 4 hours pumped absence under conditions which well‐fed did not. starved responded...

Little is known about the physiology of neurons in Caenorhabditis elegans. Using new techniques for situ patch-clamp recording C. elegans, we analyzed electrical properties an identified sensory neuron (ASER) across four developmental stages and 42 unidentified at one stage. We find that ASER nearly isopotential fails to generate classical Na+ action potentials. Rather, displays a high sensitivity input currents coupled depolarization-dependent reduction may endow with wide dynamic range....

The Caenorhabditis elegans gene eat-4 affects multiple glutamatergic neurotransmission pathways. We find that encodes a protein similar in sequence to mammalian brain-specific sodium-dependent inorganic phosphate cotransporter I (BNPI). Like BNPI the rat CNS, is expressed predominantly specific subset of neurons, including several proposed be glutamatergic. Loss-of-function mutations cause defective chemical transmission but appear have little effect on other functions neurons. Our data...

Abstract We studied the control of pharyngeal excitation in Caenorhabditis elegans. By laser ablating subsets nervous system, we found that MC neuron type is necessary and probably sufficient for rapid pumping. Electropharyngeograms showed transmits excitatory postsynaptic potentials, suggesting acts as a neurogenic pacemaker Mutations genes required acetylcholine (ACh) release an antagonist nicotinic ACh receptor (nAChR) reduced pumping rates, nAChR transmission. To identify...

To gain insights into the genetic cascades that regulate fat biology, we evaluated C. elegans as an appropriate model organism. We generated worms lack two transcription factors, SREBP and C/EBP, crucial for formation of mammalian fat. Worms deficient in either these genes displayed a lipid-depleted phenotype—pale, skinny, larval-arrested stores. On basis this phenotype, used reverse screen to identify several additional play role worm lipid storage. Two encode components mitochondrial...

Autophagy is a major pathway used to degrade long-lived proteins and organelles. thought promote both cell organism survival by providing fundamental building blocks maintain energy homeostasis during starvation. Under different conditions, however, autophagy may instead act death through an autophagic distinct from apoptosis. Although several recent papers suggest that plays role in death, it not known whether can cause the of organism. Furthermore, why acts some instances but others poorly...

SUMMARY Pumping of the C. elegans pharynx transports food particles(bacteria) posteriorly. We examined muscle motions to determine how this posterior transport is effected. find that middle section pharynx, anterior isthmus, are delayed relative section, corpus. Simulations in which particles assumed move at mean fluid velocity when not captured by walls pharyngeal lumen show isthmus do indeed cause net particle transport; however, amount much less than real pharynx. propose geometry forces...

Abstract Mutations in eat-2 and eat-18 cause the same defect C. elegans feeding behavior: pharynx is unable to pump rapidly presence of food. EAT-2 a nicotinic acetylcholine receptor subunit that functions pharyngeal muscle. It localized synapse between muscle main excitatory motor neuron MC, it required for MC stimulation encodes small protein has no homology previously characterized proteins. single transmembrane domain short extracellular region. Allele-specific genetic interactions...

ABSTRACT Previous work has shown that 12 of the 14 types neurons in Caenorhabditis elegans pharyngeal nervous system are collectively but not individually necessary for trapping and transport bacteria. The aim these experiments was to determine functions individual neuron by laser−killing combinations looking at effects on behavior. motor M3 sensory I5 important bacteria, as two observations. First, when both killed, is inefficient isthmus (the middle section pharynx). Second, sufficient...